Lutger Wrote:

> Sean Kelly wrote:
> 
> > Sean Kelly Wrote:
> > 
> >> Leandro Lucarella Wrote:
> >> 
> >> > Not quite ready for prime-time yet, but I think it's in a stage when it
> >> > could be interesting anyway (at least for developers or people that want
> >> > to experiment):
> >> > http://llucax.com.ar/blog/blog/post/-1a4bdfba
> >> 
> >> Nice work!  I've gotten this to compile as the GC for druntime using D2 but have ran into a snag.
> > 
> > Okay, all fixed.  Porting the GC to D2 was more work than porting it to druntime specifically.  There are still a few hacks in place to work around const issues and I faked the PointerMap stuff, but the GC seems to work just great.  I'll have to find a reasonable performance test for comparison.  Oh, I'll send you the modified code as well.
> 
> Are you going to integrate it in druntime?

Dunno.  For now, I've just sent my modified copy to Leandro and the druntime list for people to play with.  It seems quite promising though.

== Quote from Sean Kelly (sean@invisibleduck.org)'s article
> Lutger Wrote:
> > Sean Kelly wrote:
> >
> > > Sean Kelly Wrote:
> > >
> > >> Leandro Lucarella Wrote:
> > >>
> > >> > Not quite ready for prime-time yet, but I think it's in a stage when it
> > >> > could be interesting anyway (at least for developers or people that want
> > >> > to experiment):
> > >> > http://llucax.com.ar/blog/blog/post/-1a4bdfba
> > >>
> > >> Nice work!  I've gotten this to compile as the GC for druntime using D2 but have ran into a snag.
> > >
> > > Okay, all fixed.  Porting the GC to D2 was more work than porting it to druntime specifically.  There are still a few hacks in place to work around const issues and I faked the PointerMap stuff, but the GC seems to work just great.  I'll have to find a reasonable performance test for comparison.  Oh, I'll send you the modified code as well.
> >
> > Are you going to integrate it in druntime?
> Dunno.  For now, I've just sent my modified copy to Leandro and the druntime
list for people to play with.  It seems quite promising though.

Been meaning to ask, what does this GC do with regard to precise scanning?  Is it substantially less conservative than the current D2 GC?

On 09/15/2010 07:00 PM, Sean Kelly wrote:
> Lutger Wrote:
>
>> Sean Kelly wrote:
>>
>>> Sean Kelly Wrote:
>>>
>>>> Leandro Lucarella Wrote:
>>>>
>>>>> Not quite ready for prime-time yet, but I think it's in a stage when it
>>>>> could be interesting anyway (at least for developers or people that want
>>>>> to experiment):
>>>>> http://llucax.com.ar/blog/blog/post/-1a4bdfba
>>>>
>>>> Nice work!  I've gotten this to compile as the GC for druntime using D2 but
>>>> have ran into a snag.
>>>
>>> Okay, all fixed.  Porting the GC to D2 was more work than porting it to
>>> druntime specifically.  There are still a few hacks in place to work around
>>> const issues and I faked the PointerMap stuff, but the GC seems to work just
>>> great.  I'll have to find a reasonable performance test for comparison.  Oh,
>>> I'll send you the modified code as well.
>>
>> Are you going to integrate it in druntime?
>
> Dunno.  For now, I've just sent my modified copy to Leandro and the druntime list for people to play with.  It seems quite promising though.

There's a discussion on digitalmars.D about a D program being slower than the equivalent Python script because of the GC. Would be a good test bed!

Andrei

On 9/15/10 22:22 CDT, Andrei Alexandrescu wrote:
> On 09/15/2010 07:00 PM, Sean Kelly wrote:
>> Lutger Wrote:
>>
>>> Sean Kelly wrote:
>>>
>>>> Sean Kelly Wrote:
>>>>
>>>>> Leandro Lucarella Wrote:
>>>>>
>>>>>> Not quite ready for prime-time yet, but I think it's in a stage
>>>>>> when it
>>>>>> could be interesting anyway (at least for developers or people
>>>>>> that want
>>>>>> to experiment):
>>>>>> http://llucax.com.ar/blog/blog/post/-1a4bdfba
>>>>>
>>>>> Nice work! I've gotten this to compile as the GC for druntime using
>>>>> D2 but
>>>>> have ran into a snag.
>>>>
>>>> Okay, all fixed. Porting the GC to D2 was more work than porting it to
>>>> druntime specifically. There are still a few hacks in place to work
>>>> around
>>>> const issues and I faked the PointerMap stuff, but the GC seems to
>>>> work just
>>>> great. I'll have to find a reasonable performance test for
>>>> comparison. Oh,
>>>> I'll send you the modified code as well.
>>>
>>> Are you going to integrate it in druntime?
>>
>> Dunno. For now, I've just sent my modified copy to Leandro and the
>> druntime list for people to play with. It seems quite promising though.
>
> There's a discussion on digitalmars.D about a D program being slower
> than the equivalent Python script because of the GC. Would be a good
> test bed!

This is what I was referring to.

http://rounin.livejournal.com/21815.html

The author makes quite a few good points comparing D and Python in expressiveness and performance.


Andrei

Andrei Alexandrescu Wrote:
> 
> There's a discussion on digitalmars.D about a D program being slower than the equivalent Python script because of the GC. Would be a good test bed!

I was playing with that yesterday, but there was too much setup required for a quick test (it compared an MD5 has of a directory tree to the current directory tree).  I'll revisit it though, since it seems a good starting point.

dsimcha Wrote:

> == Quote from Sean Kelly (sean@invisibleduck.org)'s article
>
> > Dunno.  For now, I've just sent my modified copy to Leandro and the druntime
> list for people to play with.  It seems quite promising though.
> 
> Been meaning to ask, what does this GC do with regard to precise scanning?  Is it substantially less conservative than the current D2 GC?

Its gc_malloc, etc, accept a PointerMap type which I assume is used for precise scanning, but I couldn't find a definition of PointerMap in the GC code or other obvious locations so I disabled it for now.  I assume it's from the precise scanning patch and that I can get whatever else is needed from there.  For now, I just wanted a functional port to test.

Leandro Lucarella, el 10 de septiembre a las 09:26 me escribiste:
> Bernard Helyer, el 10 de septiembre a las 04:49 me escribiste:
> > Very nice. I've been reading your posts on this with interest.
> > 
> > How much work would be involved in porting this to druntime?
> 
> Is hard to tell since I didn't followed druntime development very closely lately, but both are based on the same code, so probably not too much work should be involved.

BTW, I just saw there were quite a few replies to this threads while my internet connection was down for a couple of weeks (just after I posted this), that I didn't received.

I'm sorry about the silence, I'll try to reply the things that might still be of interest, and I'll take this opportunity to say that CDGC is "finished", see the blog post for (a few) more details: http://llucax.com.ar/blog/blog/post/-7454ab1d


Now the replies.

David Simcha asked:

> Been meaning to ask, what does this GC do with regard to precise scanning?  Is it substantially less conservative than the current D2 GC?

Yes, if the compiler support is there. It uses the patch to DMD posted by wm4 to scan the heap precisely. See bug 3463 for details: http://d.puremagic.com/issues/show_bug.cgi?id=3463


Andrei Alexandrescu said:

> There's a discussion on digitalmars.D about a D program being slower than the equivalent Python script because of the GC. Would be a good test bed!
>
> http://rounin.livejournal.com/21815.html

I'll try it when I have some time. I wouldn't expect much improvement because it only uses AAs that doesn't get scanned precisely yet (IIRC from wm4 patch), but there are a few optimizations that could help with dynamic arrays (which are also used frequently). We'll see :)

OTOH, Dil does a lot of string processing using too AAs and dynamic
arrays (AFAIK) and the improvement is huge using CGGC :). As a sample,
attached are the results for a Dil run generating all the Tango docs,
using 1 CPU (using more CPUs is a little faster), for the Tango basic GC
(TBGC) and several configurations of the CDGC. The file named "time"
measures the total run time (i.e. the throughput), the one named "stw"
measures the maximum stop-the-world pause (i.e. the time no thread can
run) and the file named "pause" measures the maximum time the GC will
actually block the program (i.e. the maximum real latency). All in
seconds, for 50 runs (the run time) and 20 runs (the pause time),
minimum is in black, maximum in white, and the mean is centered between
2 std deviations (in grey).


-- 
Leandro Lucarella (AKA luca)                     http://llucax.com.ar/
----------------------------------------------------------------------
GPG Key: 5F5A8D05 (F8CD F9A7 BF00 5431 4145  104C 949E BFB6 5F5A 8D05)
----------------------------------------------------------------------
Hey you, out there on your own
Sitting naked by the phone
Would you touch me?

On Fri, 08 Oct 2010 04:25:30 +0400, Leandro Lucarella <luca@llucax.com.ar> wrote:

> Leandro Lucarella, el 10 de septiembre a las 09:26 me escribiste:
>> Bernard Helyer, el 10 de septiembre a las 04:49 me escribiste:
>> > Very nice. I've been reading your posts on this with interest.
>> >
>> > How much work would be involved in porting this to druntime?
>>
>> Is hard to tell since I didn't followed druntime development very
>> closely lately, but both are based on the same code, so probably not too
>> much work should be involved.
>
> BTW, I just saw there were quite a few replies to this threads while my
> internet connection was down for a couple of weeks (just after I posted
> this), that I didn't received.
>
> I'm sorry about the silence, I'll try to reply the things that might
> still be of interest, and I'll take this opportunity to say that CDGC is
> "finished", see the blog post for (a few) more details:
> http://llucax.com.ar/blog/blog/post/-7454ab1d
>
>
> Now the replies.
>
> David Simcha asked:
>
>> Been meaning to ask, what does this GC do with regard to precise
>> scanning?  Is it substantially less conservative than the current D2
>> GC?
>
> Yes, if the compiler support is there. It uses the patch to DMD posted
> by wm4 to scan the heap precisely. See bug 3463 for details:
> http://d.puremagic.com/issues/show_bug.cgi?id=3463
>
>
> Andrei Alexandrescu said:
>
>> There's a discussion on digitalmars.D about a D program being slower
>> than the equivalent Python script because of the GC. Would be a good
>> test bed!
>>
>> http://rounin.livejournal.com/21815.html
>
> I'll try it when I have some time. I wouldn't expect much improvement
> because it only uses AAs that doesn't get scanned precisely yet (IIRC
> from wm4 patch), but there are a few optimizations that could help with
> dynamic arrays (which are also used frequently). We'll see :)
>
> OTOH, Dil does a lot of string processing using too AAs and dynamic
> arrays (AFAIK) and the improvement is huge using CGGC :). As a sample,
> attached are the results for a Dil run generating all the Tango docs,
> using 1 CPU (using more CPUs is a little faster), for the Tango basic GC
> (TBGC) and several configurations of the CDGC. The file named "time"
> measures the total run time (i.e. the throughput), the one named "stw"
> measures the maximum stop-the-world pause (i.e. the time no thread can
> run) and the file named "pause" measures the maximum time the GC will
> actually block the program (i.e. the maximum real latency). All in
> seconds, for 50 runs (the run time) and 20 runs (the pause time),
> minimum is in black, maximum in white, and the mean is centered between
> 2 std deviations (in grey).
>
>

Hi, Leandro!

I tried using your GC under D2/Windows, and unfortunately it crashes with Access Violation (I used a version modified by Sean as a starting point with little changes to fix compilation error).

Are there any plans supporting it? I'm willing to help with testing it as much as I can.

Thanks!

Denis Koroskin, el  8 de octubre a las 05:14 me escribiste:
> I tried using your GC under D2/Windows, and unfortunately it crashes with Access Violation (I used a version modified by Sean as a starting point with little changes to fix compilation error).
> 
> Are there any plans supporting it? I'm willing to help with testing it as much as I can.

As I told to Sean, I tried my best to not break Windows support very much, but I don't have a Windows environment to test with (and to very interested on creating one to be honest, sorry :S). But I am very interested on accepting patches to make Windows work (and improvements).

Testing the GC on Windows might not be very tempting though, as the main improvement is based on the fork(2) system call, which is not available on Windows, so all the fun options will be disabled there. The only thing that might worth trying in Windows is the precise scanning (well, there are some other minor optimizations that proved useful).

-- 
Leandro Lucarella (AKA luca)                     http://llucax.com.ar/
----------------------------------------------------------------------
GPG Key: 5F5A8D05 (F8CD F9A7 BF00 5431 4145  104C 949E BFB6 5F5A 8D05)
----------------------------------------------------------------------
Yo soy Peperino, mártir latino, venid al asado pero traed el vino.
	-- Peperino Pómoro

Leandro Lucarella, el  8 de octubre a las 01:44 me escribiste:
> Denis Koroskin, el  8 de octubre a las 05:14 me escribiste:
> > I tried using your GC under D2/Windows, and unfortunately it crashes with Access Violation (I used a version modified by Sean as a starting point with little changes to fix compilation error).
> > 
> > Are there any plans supporting it? I'm willing to help with testing it as much as I can.
> 
> As I told to Sean, I tried my best to not break Windows support very much, but I don't have a Windows environment to test with (and to very interested on creating one to be honest, sorry :S). But I am very interested on accepting patches to make Windows work (and improvements).
> 
> Testing the GC on Windows might not be very tempting though, as the main improvement is based on the fork(2) system call, which is not available on Windows, so all the fun options will be disabled there. The only thing that might worth trying in Windows is the precise scanning (well, there are some other minor optimizations that proved useful).

BTW, I've put up a small (Linux/POSIX) HOWTO to easily try CDGC. People interested on trying CDGC might find it useful:

http://llucax.com.ar/blog/blog/post/-4d1fefb4


-- 
Leandro Lucarella (AKA luca)                     http://llucax.com.ar/
----------------------------------------------------------------------
GPG Key: 5F5A8D05 (F8CD F9A7 BF00 5431 4145  104C 949E BFB6 5F5A 8D05)
----------------------------------------------------------------------
Cuando el Mártir estaba siendo perseguido y aglutinado por los
citronetos, aquellos perversos que pretendian, en su maldad, piononizar
las enseñanzas de Peperino.
	-- Peperino Pómoro